without the spots beneath, and the red marks on the margin of the posterior wings, L.*

Thymele málvæ, grizzled skipper, L. _T. Tàges, dingy skipper, L. Pamphila sylvanus, large skipper. P. cómma, silver-spotted skipper. P. línea, small skipper.

P. S. Since the above list was prepared, I have been favoured with an inspection of Miss Harvey's cabinet, who resides at Upper Deal; and observed therein the following species, in addition to those already enumerated, viz. : — Melitæ a Selène, Dictýnna, and A'rtemis; all of which, I was informed, had been taken in the neighbourhood of Deal or Canterbury. The same lady also showed me a fine specimen of Còlias Hyale, taken in June last, in a field of clover or saintfoin, near Deal; and likewise a specimen of Papílio Machàon, which she had reared from the caterpillar the only instance that had come to her knowledge of the insect occurring in that vicinity. Vanéssa Antìopa had been seen settling on a wall in Admiral Harvey's garden, in the month of August; but my intelligent informer was unable to capture it. A single specimen also of V. c. álbum had been observed in the same situation last summer, which is considered a very rare insect in that part of the country. W. T. B.

Allesley Rectory, Nov. 10. 1831.

ART. VIII. Some Account of a Species of A'carus (?) which infests Butterflies. By the Rev. W. T. BREE, M.A.

Sir,

HAVING, in the preceding article, given a list of Papilionida found near Dover; as an appropriate sequel to that list, and intimately connected with the subject of it, I now take occasion to notice a small parasitical insect (fig. 74., and magnified fig. 75.), which I suppose to belong to the genus A'carus +: I

sex vary considerably in size, and the females exceedingly so in colour; some having the wings brown above, and others more or less of a fine purplish blue. Of the latter sex, I observed some remarkably blue specimens, in a perfectly fresh state, in the Castle meadow, the last week in September.

Since writing the above, I have met with the following account, in Professor Rennie's Insect Miscellanies (p. 27.), of what I have no doubt is the same insect:- 66 A species," he says, "of this family (Acarina,) probably the red tick (Pediculus coccineus Scopoli), or a mite (Léptus Phalángii) described by De Geer, appears to be much more indiscriminate [than the harvest bug, Léptus autumnàlis,] in its tastes; for, during the summer of 1830, we found it at Havre de Grace, infesting insects of the ost different families. It particularly abounded on the marbled butterfly

speak doubtfully, however, not having at the present moment an opportunity of referring to any works on natural history. Were the insect I allude to known to Linnæus*, I would almost venture an opinion that he would have named it A'carus lepidopterorum but whether or not he describes the species in question, or any other under that name, my memory does not serve me. I think I have formerly observed this A'carus (?) adhering to Hippárchia Galathèa, but never in the same abundance in which it is to be met with in this neighbourhood: here the butterflies are, if I may be allowed the expression, absolutely lousy with it. I have no microscope at hand, save an ordinary pocket lens, to enable me to give an accurate and minute description of the little parasite; its general appearance is bright red, about the colour of sealing-wax; in shape oblong, cylindrical, but somewhat flattened beneath; and about the size, or nearly so, of one of the small seeds of the prince's feather (Amaránthus hypochondrìacus); legs (six in number?) and antennæ so minute as not to be visible to the naked eye; when crushed, it gives out a fine orange colour. It adheres in clusters under the eyes of lepidopterous insects,

(Hipparchia Galathea Leach), so that many of them were scarcely able to fly from the exhaustion caused by these little bloodsuckers; and so pertinaciously did they retain their hold, that several of them now adhere to the specimens of the butterfly in our cabinet. What was most remarkable, although the ringlet butterly (H. Hyperánthus) was plentiful at the same time, and is similar in food and habits, not one of the parasites was found on some hundreds which we caught expressly to ascertain the fact. This appears the more strange, as several dragon flies (Libellulina MacLeay) were found as much infested with them as the marbled butterfly. We also, more than once, found them on field crickets, ants, and beetles, and once on a harvest spider (Phalángium Opílio)." This account corresponds in the main with the Dover A'carus, save that I could observe the parasite on no other than on lepidopterous insects; nor did the butterflies infested with it appear to me to be in the least incommoded in their flight by such encumbrance, not even the small blues (Polyómmatus I'carus and Adonis), though they had frequently five or six or more A'cari adhering to them: on the contrary, they sported about as briskly as usual, and to appearance seemed quite unconcerned. I may remark, too, that, with respect to Hipparchia Galathèa, that insect at the best of times evinces no great power of wing; but usually flies about heavily and slowly, frequently settling on some stalk of grass, &c., and on such occasions keeping its wings expanded. Unless Professor Rennie bore this circumstance in mind, it is possible that he may have very naturally attributed the ordinary heavy flight of Galathea to the encumbrance caused by the A'cari.

On subsequently referring to Linnæus, I think it not improbable that our insect may be the same which he describes by the name of A'carus gymnopterorum (Fauna Suecica, edit. altera, p. 483.); and of which he says "habitat in culicibus, apibus, aliisque, uti sequens acarus [4. coleoptratòrum] in coleoptratis." It infests gnats, bees, and other insects, as the following species, A. coleoptratòrum, does coleopterous.

VOL. V.- No. 26.

between the legs, at the base of the wings, and at the junctures of the thorax with the head and with the abdomen, both above and beneath. The insects on which I have chiefly observed it are, Hipparchia Galathèa (fig. 74. b) and Janira, Polyómmatus I'carus (a), and Adònis, Anthrócera filipéndulæ, and,

in one instance, Cynthia cárdui, but particularly Hipparchia Galathèa. The common white butterflies (Póntia brássica and ràpæ) appear to be free from this pest; at least, I have not been able to detect a single Acarus on any one of the numberless individuals of those species which I have examined for that express purpose. It is no uncommon occurrence, to see the small blue butterflies (Polyómmatus l'carus and Adònis) flying about, as it should seem, with perfect ease and indifference, and apparently in full enjoyment of life, while some half dozen of these Acari are adhering to them, and deriving sustenance from the juices of their slender bodies. If we were to be encumbered with vermin of a proportional magnitude, it would be like having a number of creatures as large, perhaps, as moderately sized lobsters sticking to our flesh, and preying upon our vitals. Perhaps some of your correspondents may be able to throw more light on the history of this little insect. It would form, I may suggest, a fit subject for the exercise of our friend Mr. Westwood's microscopic acumen. How, for example, does the A'carus first gain a lodgement on the Lepidoptera it infests? And how is the race continued after the butterflies die in the autumn? Is the insect most generally found to abound in chalk districts? &c. &c. I may observe, that, in the autumn, the A'cari had nearly disappeared from the butterflies, long before the latter had ceased to fly abroad.

It may be proper to add, that, of the specimens of Acari which I send herewith, some have been gummed on paper, in order the better to exhibit them, and others have been fixed by the same means in their natural position, just as they Thered to the butterflies on which they were found: in the

latter case, many of the A'cari had made their escape before the gum could be applied; and in both, it should be remembered that the specimens have, of course, shrunk in size since they were alive. I am, Sir, yours, &c.

Dover, Sept. 30. 1831.

W. T. BREE.

SOME of the insects were in a paper, others inside a dry phial, and the remainder adhering to the bodies of Polyómmatus Icarus (fig. 74. a), Hipparchia Galathèa (fig. 74. b), and Hippárchia Janìra, which has been deemed too common to figure. Mr. Sowerby, in making the drawings, observed that the A'cari out of either the phial or the

paper had long bristly legs, while those taken off 75 the bodies of the butterflies had smaller, and smoother, and less obvious legs. Fig. 75. represents a magnified figure of one of the latter, which Mr. Sowerby regrets is less accurate than it should be; as, from the insects coming to him in a dried and shrivelled state, the parts were discernible far less perfectly than they would have been had the insects been preserved in spirits.-J. D.

ART. IX. Remarks on a Species of Lepas cast ashore near Liverpool on Nov. 7. 1831. By THOMAS WEATHERILL, Esq. M.D.

Sir,

I HAVE been a subscriber to your Magazine from its commencement, but have not observed in it any notice of the genus Lèpas, or acorn-shell. Perhaps the following rough sketch of a species of this family of curious creatures may be acceptable to your readers. Fig. 76. c is intended to represent a piece of wood, with a number of them attached to it, which was taken from a large log of pine found upon the shore, near Liverpool, on the 7th of November last, during a heavy gale, and a tremendous sea from the north and west.

The log, which was about 12 ft. long, and of a proportionate thickness, and apparently the remains of a wrecked vessel, was completely covered in every part with them. It excited a great deal of curiosity, and was publicly exhibited in Liverpool as a rare and wonderful marine production.

The books which I have consulted for information contain but very indefinite and unsatisfactory descriptions of the genus Lepas, and what they do contain is so little and so

imperfect, that I have not been able to assign the present specimen to any of the species they mention. The goosebernacle (Lepas anatífera, fig. 77. p. 343.) approaches the nearest, and it may be a variety of it. I am almost, however, inclined to consider it a new species. The genus Lepas belongs to the order Vérmes testacea [worms in shells]; shell multivalvular, or of many valves, unequal, sometimes fixed by a pedicle or stem, and sometimes not. Animal, a triton, with tentacula. The species anatífera consists of five-valved shells, irregular, somewhat depressed, affixed to a pedicle, and in clusters; colour, a reddish purple, which runs into a dark brown purple near the base of the shell. The one under consideration has a shell of five valves, irregular, depressed, attached to a stem, but not in clusters; every shell having its own pedicle, which is perfectly transparent, and nearly colourless, inclining slightly to a reddish purple as it approaches the shell, and then assuming a darker purple colour, which gradually grows deeper until it reaches the base. Hence it differs from the anatífera in two very marked particulars: 1st, By having undivided and much longer stems; and, 2dly, by having a much less dense colour.

Fig.76. a is about the ordinary length and size of those cast on shore in November last. The stem is represented to be